Electric-wave transmission



J. H. HAMMOND, JR. ELECTRIC WAVE TRANSMISSION. APPLICATION FILED MAY 20, 1912. RENEWED 05c. 12, 1917.

- Patented June 20, 1922.

ATTORNEYS UNITED STATES PATENT OFFICE.

ELECTRIC-WAVE TRANSMISSION.

Specification of Letters Patent. Patented J 20; 1

Application filed May 20, 1912, Serial No. 698,441. Renewed December 12, 1917. Serial No. 206,856.

To all whom it may concern Be it known that I, JoHN HAYS HAM- MOND, J r., a citizen of the United States, residing at Gloucester, in the State of Massachusetts, have invented certain new and useful Improvements in Electric-Vave Transmissions, of which the following is a specification.

My invention relates to the employment'of liquid or gaseous elements to replace the usual solid type of antenna used for transmitting and receiving in radio telegraphy and telephony, and relates more particularly to a method for ultilizing such liquid and gaseous antennae in a practical way. The idea of using a liquid or gaseous antenna with the ordinary method of tuning by means of wave frequencies in radio telegraphy is not new, but it is obvious that in any kind of a wind, and also owing to other causes, the capacity of either a liquid or a gaseous antenna would be continually changing, and as the frequency of the waves emitted from an antenna depends upon the product of its inductance and capacity, it follows that by the ordinary method of tuning, resonance between transmitting and receiving antennae would be impossible.

By my invention, as will hereafter appear, I have made possible a method of tuning by wave-group frequency, so that changes in the wave length of the waves emitted and received will not affect the selectivity between stations. 1

Referring to the drawings, Figure 1 shows a transmitting station with a fluid antenna.

Figure 2 shows a receiving station with a fluid antenna.

Figure 3 shows a modified form of receiving station with a fluid antenna.

Figure 4 shows a modified form of transmitting station with a fluid antenna.

Figure 5 shows another modified form of transmitting station with a fluid antenna.

In Figure 1, B is an alternating-current generator supplying current through the key K to the transformer TT The coil T supplies current to the oscillatory circuit C S I L, including the condenser C, the interrupter I, forming a rotary spark gap at S, and the coil .L which is inductively coupled with the antenna A by means of the. helix L The antenna A consists of a stream of conducting fluid forced through the tubular helix L by the pump P from an inlet D. E is a ground connection. The stream ancurved, or have any other suitable direction or shape. The tubular helix L may consist of copper or any other suitable material.

The electric waves emanating from the circuit C S I L are broken up into groups, having a definite group frequency, by the rotary spark gap I S, and are thus transmitted by the antenna A, so that although the length of the waves may vary, owing to the varying capacity of the antenna, the wave-group frequency will remain constant.

In Figure 2, B is a fluid receiving antenna, consisting of a stream of suitable conducting fluid forced through the tubular helix L by the pump P from the inlet D L is inductively coupled, by means of the coil L to the untuned circuit L R L. The

oscillations in L R L are converted by means of the rectifier R, to unidirectional current impulses having a frequency corresponding to the group frequency, or amplitude variation frequency, of the transmitting station. The circuit L Q 0, containing the variable condenser Chis inductively coupled to coil L and is tuned to the wave-group frequency of the transmitting station. The receiving telephone Q enables signals from the transmitting station to be heard, and the relay N receives unidirectional current from the circuit L Q C through the rectifier R and the local circuit of N may be used for the operation of suitable mechanisms.

In Figure 3, the fluid antenna B of the receiving station consists'of a stream forced through the tubular helix L by the pump P from the inlet D The circuit L C is broadly tuned so as to respond to waves of different lengths, and is inductively coupled with the antenna B by means of helix L and coil L". A rectifier R permits unidirectional current impulses to flow through the telephone receiver Q and the electro magnet U. The vibrating reed V is tuned to the group frequency, or the periodic amto that in Figure 1. The alternating-current generator G excites the field winding F of high-frequency alternator H, and so produces a periodic variation of amplitude in the current from II. This current passes through the key K to the coil L which is inductively coupled with the tubular helix L connected with the antenna A Electric waves having a specific periodic variation of amplitude are thus emitted by the antenna A In Figure 5, the alternator I-I supplies high frequency current to the coil L through the key K The coil L is inductively coupled with the tubular helix L which is connected with the fluid antenna A The motor M is mechanically connected with the coil L and rotates the latter so as to cause periodic variations of amplitude in the high-frequency oscillations induced in the helix L and antenna A and radiated from the latter.

In the apparatus shown, the pump for forcing the fluid through the helix and forming the stream antenna may be replaced by a gravity system or by any other suitable apparatus, and the means for producing variations in amplitude of the electric waves or for breaking the waves up into groups may be different from those shown.

In general, I do not confine myself to the particular apparatus and mechanisms here shown, but various changes and modifications, within the knowledge of those skilled in the art, may be made in the particular apparatus and mechanisms shown and described herein, without departing from the spirit of my invention, provided the means set forth in the following claims he employed.

I claim:

1. In a system of electric wave transmission, the combination with a fluid antenna automatically and irregularly varying in capacity, of means for generating continuous uniform oscillations associated with said antenna, and means for periodically interrupting said oscillations whereby groups of Waves of constantly and irregularly varying amplitude are radiated.

2. In a system of electric wave transmission, the combination with a liquid antenna automatically and irregularly varying in capacity, of means for generating continuous uniform oscillations associated with said antenna, and means for periodically interrupting said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated.

3. In a system of electric wave transmis sion, the combination with a fluid antenna automatically and irregularly varying in ca pacity, of means for generating continuous oscillations associated with said antenna, means for periodically interrupting said 05- cillations whereby groups of Waves of constantly and irregularly varying amplitude are radiated, and means for receiving said waves including a fluid antenna automatically and irregularly varying in capacity, and means associated therewith tuned to the group frequency of said waves.

4. In a system of electric wave transmission, the combination with a liquid antenna automatically and irregularly varying in capacity, of means for generating continuous oscillations associated with said antenna, means for periodically interrupting said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated, and means for receiving said waves including a fluid antenna automatically and irregularly varying in capacity, and means associated therewith tuned to the group frequency of said waves.

5. In a system of electric wave transmis sion, the combination with a fluid antenna automatically and irregularly varying in electrical length, of means .for generating continuous uniform oscillations associated with said antenna, and means for periodically interrupting said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated by said antenna.

6. In a system of electric wave transmission, the combination with an antenna auto matically and irregularly varying in capacity, of means for generating continuous uniform oscillations associated with said antenna, and means for periodically interrupting said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated by said antenna.

7. In a system of electric wave transmis sion, the combination. with antenna automatically and irregularly varying in electrical length, of means for generating con tinuous uniform oscillations associated with said antenna, and means for periodically interrupting said oscillations whereby groups of waves of constantly and irregularly vary ing amplitude are radiated bysaid antenna.

8. In a system for the transmission of electro-radiant energy, the combination with a fluid antenna automatically and irregularly varying in electrical length, of means for generating continuous oscillations associated with said antenna, and means for periodically modifying said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated by said antenna.

9. In a system for the transmission of electro-radiant energy, the combination with periodically modifying said oscillations whereby groups of waves of constantly and irregularly varying amplitude are radiated by said antenna.

10. A method for the transmission of electro-radiant energy which consists in generating continuous uniform oscillations, periodically interrupting said oscillations to form groups of uniform oscillations and causing a radiation of groups of waves of constantly and irregularly varying amplitude as the result of the action of said groups ofuniform oscillations.

11. A method for the transmission of electro-radiant energy which consists in generating continuous uniform oscillations, periodically interrupting said'oscillations to form groups of uniform oscillations and causinga radiation of groups of waves of constantly and irre ularly varying amplitude as the result of the inductive action of said groups of uniform oscillations.

12. The method of transmitting electroradiant energy which consists in generating continuous uniform electrical oscillations and causing'the radiation of groups of wax'es of constantly and irregularly varying amplitude as the result of the action of said periodically modified uniform oscillations.

This specification signed and witnessed this 11th day of May A. D., 1912.

JOHNHAYS HAMMOND, JR. Witnesses:

MABEL J. CooPER, DOROTHY F. DAMES. 

